letting chicks into the run

My chicks have now been out of the laundry room and in the coop for a week and I was wondering if I can let them into the run yet? I have been putting them in a portable run when I get home from work so they can get some outside time. They need to climb a pretty steep ramp, a flat board with wooden rails as tred, to get back in so I'm not sure if they would know to do that. They are all fully feathered and fluttering around so very mobile. Thanks for your advice.

I think what you have in mind will work real good. The one thing you mentioned that I would change/fix is the steep ramp. Would there be any way that you could build a small landing for that steep ramp and then add another ramp from the ground up to the landing? This is why we big people have such landing on our high decks, to take out the steep and give us a rest.